I have a 29 gallon biocube that I really enjoy--but I only have two fish in it, a yellow watchman goby (with a pistol shrimp) and cardinal pajama fish. I originally added a couple of other pajama fish, but they were beaten to death by the one that remains. I'd love to add another fish to the mix--one that swims about freely--but can't figure out what to add... it's a reef tank with corals, macroalge, and so on... suggestions welcome. Thank you so much for your help. The tank is two years old.



